Meet one of Baylor’s space medicine pioneers and rising stars

Baylor College of Medicine’s Center for Space Medicine (CSM) educates and conducts research on the challenges and health hazards of human spaceflight – and is always learning more about this evolving field.

Dr. Mohammad Hirzallah, assistant professor in the Center for Space Medicine, toggles between being a principal investigator and a co-investigator on various projects and providing neurocritical care for patients.

Hirzallah did not originally intend to pursue or conduct research in space medicine, but space medicine was determined to find him. While researching intracranial pressure at UTHealth Houston’s Institute for Stroke and Cerebrovascular Diseases, Hirzallah noticed a pattern of NASA funding for non-invasive intracranial pressure modalities, which led him to discover space medicine. Realizing the overlap aerospace medicine had with his work and his clinical interests, he followed his interest and found Baylor.

“I found that there were people at UTHealth Houston who also had the research,” Hirzallah said. “I met Larry [Kramer], he introduced me to some of the people in Baylor, and we talked about space medicine research. It was around that time when I was like, okay, this is really interesting, and it overlaps with a lot of my interests.”

Hirzallah’s entry into Baylor was the result of multiple timelines aligning as he ventured to do a fellowship in neurocritical care in Pittsburg. Upon completion of his fellowship, his current position was being advertised by Baylor, which he calls a “happy coincidence.”

In addition to patient care in the neuro-ICU, Hirzallah serves as a co-investigator with CSM associate professor Dr. Eric Bershad on a long-term astronaut brain health study. He has also worked with the Translational Research Institute for Space Health (TRISH) on multiple projects, including the EXPAND (Enhancing eXploration Platforms and Analog Definition) Program and CADRE (Commercial Astronaut Data REpository).

In 2021, researchers decided to do more biomedical research for Inspiration4, the first all-private orbital space mission. This entailed consolidating research projects from six different institutions over approximately six months into one database and biorepository. Hirzallah’s role, along with Bershad’s, was pivotal to the creation of EXPAND, putting projects together into a singular protocol to create a single consent form for astronauts, which then resulted in a model for subsequent space flights.

Hirzallah also serves as principal investigator on an ongoing TRISH project that evaluates dual-use countermeasures that can be used to protect astronauts from the effects of spaceflight-associated neuro-ocular syndrome (SANS) and also protect ICU patients from the effects of elevated intracranial pressure. He is also active in research on the optic sheath nerve diameter, which has benefits for both addressing SANS and neurocritical care. He is currently collaborating with BARDA (Biomedical Advanced Research and Development Authority), General Electrics (GE), and TRACK-TBI (Transforming Research and Clinical Knowledge in Traumatic Brain Injury) to further develop optic nerve sheath diameter ultrasonography for use in traumatic brain injury.

“You put an ultrasound probe over the eye and capture an image of the nerve and that sheath since it’s expected to expand when the pressure goes up in your brain,” Hirzallah said. “One of the first reported SANS manifestations is that astronauts started having distended optic nerve sheaths. It is also useful for my day job because it’s a non-invasive way to get a general idea of how the pressures inside a patient’s brain are behaving.”

Hirzallah’s fascination with space continues beyond space medicine research. As he would say, his “No. 1 hobby is collecting hobbies.” For example, he enjoys hiking, flying his drone, scuba diving and bouldering. One hobby existed even before his fascination with space medicine started.

“One of the things that really got me into the outdoors is I really like astrophotography,” he said. “Just taking photos of the Milky Way. You can do a lot of that in Texas.”

But to describe his involvement in space medicine research, Hirzallah borrows part of a quote from one of the Mercury Seven astronauts: “It’s something along the line of being lucky for being at the intersection of having the right opportunity at the right time and being prepared for it. I just was really interested and got really lucky at the same time,” Hirzallah said.

By Shivani Persaud, communications fellow for the Translational Research Institute for Space Health